[TG] [TG11] Lighthouse II Diagnostics Feature

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Question: I have a full Raymarine electronic suite: Dual e95’s Plotters, 260 VHF, Autopilot sp30, P70, I70’s, GPS, Quantum Radar, etc. I had a new AIS 650 series transmitter installed recently and when using the Diagnostics feature in the Lighouse software noticed something unusual. There are times the AIS650 shows and other times it doesn’t. Ive looked at the STng network stats, but it only shows transmits and recieves, no error logs. Ive verified my AIS shows is transmitting (friends boats show us on their chart plotter, Marine traffic shows as well). There are times Marine Traffice shows us as sailed out of range....and I’m wondering if it’s because my device is jumping in and out of the raymarine network?

Questions: When running the diagnostics, is it normal for a device to jump in and out of the network? Does that signify an error in cableing, device or some type of termination on the network?

is there a way to see more details on how the device is performing on the Raymarine network on the STng interface? Seems like there has to be some more advanced logging.

Thanks,
Bob Millington

[Tom - Raymarine - Moderator]

Hello Bob,

Marine Traffic's a great tool but of limited use for diagnostics because the data is (largely) volunteer-gathered from receivers in peoples' homes and businesses and depends on your line-of-sight signal level to those locations, their internet connection, antenna quality etc.

Can you describe what you mean about the device jumping in and out of the network?
Every device should be listed every time you go into Select Device (as long as you're looking on the Master MFD, since only the Master talks on SeatalkNG); if everything else is listed every time but the AIS intermittently then you may have a problem with its connection into the network indeed. I wouldn't have thought that would be the backbone or termination because you'd likely see similar issues with other STNG devices if that were the case (especially the pilot, since each pilot module continually checks for connection with the other components); if it were an STNG problem then I'd look at the spur connecting the AIS to the rest of the network. The other feasible cause is restricted supply to the AIS, so perhaps it's browning out and rebooting when it tries to transmit.

The MFD won't show detailed STNG reliability information because most CANbus transceivers filter error frames at the hardware level and only pass good messages through to the CPU: the two tools to look at CANbus reliability at the signalling level are an oscilloscope and a dedicated CAN analyser. We strongly encourage our top-level technical service dealers to have both of these tools, which will clearly show an unhealthy network and report error frame counts.
If you'd like us to look and see whether the AIS is genuinely dissappearing from the network or whether it just appears to be in the diagnostic list, by all means log a period of STNG data in Diagnostics > Interfaces > STNG/N2K > Start Buffer / Record Buffer and post it back here. I'd be happy to have a look and see what devices are sending what traffic.

Regards,
Tom

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Hi Tom,

Very much appreciate the detailed response. The reason I’m thinking the device is jumping in and out of the network is that the AIS 650 does not show up every time I run the diagnostics. The AIS is only device that isn’t showing, it seems very intermitten. I can run the disagnosiccs five times and the AIS will only show 2 or 3 times at most. On occasion the Marine Traffic AIS service I’m subscribing to shows that I have sailed out of range, and this has happened while in the harbor where I live in San Diego. Per your point below, maybe Marine Traffice is a bad guage on testing if my AIS is available or not. Ive had buddies of mine say I seem to disappear from AIS for short periods of time, but have no way to validate this point with data. My goal is really to determine why the AIS650 will not show on diagnostics every time and if there is a problem that needs to be resolved before I head out on a longer passage.

Ive attached the STNG/N2K log that was accumulated over a duration of approximately 5 minutes. Thanks again for any clues or other nuggets of wisdom.

Kind Regards,
Bob Millington

[Tom - Raymarine - Moderator]

Hi Bob,

Thanks for the log, that's great.

I hope I can set your mind at rest: whatever the reason why you're not always seeing the AIS in the Device list, is is consistently communicating on the network throughout this log-file.

To test this, I've filtered out all messages not coming from your AIS (network address 0x2b) and graphed the AIS's messages alone over time, and there's a straight-line relationship between message number and message time-stamp, no gaps (graph attached). If the AIS were stopping talking on NMEA2000 for any appreciable period, you'd see abrupt steps in the line (large gaps between time-stamps - the Y-axis - in consecutive AIS messages.) We're getting roughly 30 messages/second from the AIS, on average.

Regards,
Tom

[[email protected]]

Hi Tom,

Thanks so much! Very glad to hear the unit is communicating properly to the network. I'm confused as to why the unit shows every other time when I run diagnostics, not sure if there is a problem or not.

Thanks again, I will try and see if I can get my local service center to look at it to make sure everything is good.

Sincerely,
Bob Millington

[Tom - Raymarine - Moderator]

Hi Bob,

Each time you do 'Select Device' in the MFD's diagnostic menu, that sends an NMEA2000 Request message asking all devices to reply with their Product Information PGN. The request and response as one-shot messages, so much more likely to be affected by a network problem than repetitive (standard nav-data) messages. It might be that you have a slight problem with your STNG network (too many or too few functioning terminators, multiple power supplies, a malfunctioning device connected to the network, a crimped/twisted/corroded/loose cable or connector etc.) that's corrupting a proportion of messages. If that were the case it's probably a subtle-enough problem that it won't show up to a casual examination of an STNG log, a CANbus analyser or oscilloscope are the tools a technical dealer would use to investigate that problem, but a clue is in the fact that it's affecting the AIS only: perhaps the problem is close to the AIS's own STNG cabling. Subtle CANbus problems can easily produce intermittent faults that affect indivdual products' data. Either way, I would be confident it's not a fault with the AIS itself.

Tom